Gear sets are useful devices for transmitting torque, and changing the direction of motion as well as changing the ratio of an input motion to that of an output motion. Clearance between the teeth of one gear and the teeth of a meshing gear is often referred to as backlash. At times, backlash may manifest itself as perceptible noise attributable to rattling of gear teeth as the teeth from one gear make contact with the teeth of a mating gear. The loudness and the annoyance associated with it are proportional to the amount of backlash present.
A certain amount of backlash is required and is intentionally built into gear systems to prevent energy loss due to friction. Much of the backlash is due to dimensional variations of the various components that make up the gear system. Additional backlash is created due to normal wear of components over time. As a result, the objectionable noise tends to increase as the parts wear and the clearances increase.
While gear play noise is not indicative of a defect in the gearing system, it often proves to be an annoyance and it is desirable to minimize it as much as practicable. Accordingly there is a need in the art for gear systems that automatically eliminate backlash due to build variations as well wear of the components.